Oxychloride coating



Patented Feb. 2, 1943 UNITED I STATES PATENT orries OXYCHLOBIDE COATING George Sidney Smith, Oakland, Calif.

. No Drawing.

9 Claims.

The present invention relates to the production-of protective metal oxychloride coatings, ar-

Application October 10, 1939, Serial No. 298,866

ticles carrying said coating, and a composition of matter adapted to produce said coating,

It is well known that in the production of metal oxychloride compounds that when the ingredients functioning to produce the metal oxychloride are mixed in the presence of water, that the oxychloride is-formed, the reaction taking place very rapidly with a minimum amount of water necessary for the reaction. If the reaction mixture is properly compounded a good cement is formed. However, if an excess of water is added to the mixture to form a consistency suitable for brushing or spraying then the density and coherence of the resulting coating is destroyed. This is particularly true in the production of zinc oxychloride compounds.

The principal object of the present invention is to form on an organicor inorganic base a hard ened metal oxychloride coating by applying to the base an anhydrous mixture, including a volatile solvent therefor, said mixture having a consistency suitable for brushing or spraying, and

being adapted to form the metal oxychloride on volatilization of the solvent and in the presence of an aqueous medium; and subjecting said anhydrous coating to the action of an aqueous medium in a quantity sufiicient to form in situ by absorption a hardened oxychloride coating. In the preferred form of the invention the hardening is affected by exposure to the air for such a time to cause the volatile solvent to evaporate and the aqueous medium necessary forthe reaction to be absorbed or adsorbed by the coating.

A further object of the invention is to provide ence of an anhydrous or volatile solvent, which may also be termed a spirituous vehicle, said solvent or spirituous vehicle being adapted to take the metal chloride of the composition into solution.

It may be stated that when the anhydrous metal chloride, as for example, zinc chloride, is dissolved in an anhydrous volatile solvent therefor, as forv example, alcohol, acetone, or the like, and the resulting solution mixed with a substantially anhydrous metal oxide, the proportions being such to form a mixture having a fluid consis tency suitable for application in the manner of painting, as with brush or spray,- there is prac-.

, coating, which in the preferred form of the concrete, cement, artificial stone, and materials of like nature, generating an alkaline component with an inorganic oxychloride coating, having an acid reaction, and which is of sufficient density to prevent the alkaline component of the base material, whatever it may be, from penetrating the paint, as for example, an organic paint, subsequently applied to the metal oxychloride coating.

Another object of the invention is to provide a substantially anhydrous composition having present ingredients potentially capable of producing a metal oxychloride, the oxychloride reaction being inhibited or retarded by the presinvention, is highly water resistant and waterproof.

It may be stated that the oxychloride coating of the present invention may be applied to surfaces, such as wood, metal, stone, including concrete, cloth, porcelain, glass, plaster of Paris,

and'articles formed therefrom, as for example,

concrete bricks, concrete floors and walls and concrete laundry tubs.

While the present invention will be specifically illustrated in connection with the production of a zinc oxychloride coating, the basic steps of the present invention are applicable to the production of any oxychloride coating, the metal chloride from which the oxychloride is formed being hygroscopic in character and soluble in an anhydrous volatilizable solvent.

More specifically, zinc chloride may be dissolved in anhydrous methyl alcohol, acetone, or the like, to form a solution of 50% or less of zinc chloride. There is then added, to the solution, zinc oxide until the material is at a consistency adapted for brush painting or spraying with a spray gun. Since the ingredients, namely, the solvent, the zinc chloride and the zinc oxide, are

- anhydrous, there is substantially no chemical reaction of an oxychloride character while.the mlxture is kept free from, contact with any medium adapted to cause the oxychloride reaction to occur. If the anhydrous coating composition is exposed to the atmosphere, the volatile solvent begins to evaporate and the zinc chloride being hygroscopic absorbs sufficient moisture from the atmosphere, over a period of time, to cause the zinc chloride and 'zinc oxide to chemically react and form zinc oxychloride compounds. It-ls desired to point out that the anhydrous compositionmay contain ingredients which will in situ produce the zinc oxychloride coating. While, obviously, the most satisfactory method at the present time of forming the oxychloride coating is to ating conditions and, therefore, a solution which carries more than 50% of zinc chloride may be used.

In general, the coating composition may be applied to concrete, artificial stone, or other surfaces, and allowed to set until the evaporation of the volatile solvent is complete, said evaporation usually taking from about one to two hours, or even less. Obviously, the evaporating and setting time of the coating will vary in accordance with the character of the metal chloride constituent, the oxygen-containing constituent, the solvent, and, to some extent, the base material to which the coating is applied. Therefore, the above time is to be taken by way ofillustration and not by way of limitation.

While, in some cases, a single coating will be sufllcient, usually it is desirable, after the first coating has set, to apply-a second coating and keep the same under undisturbed conditions for a sufficient length of time, as for example, twenty-four to seventy-two hours, or longer, until the volatile solvent has evaporated and the zinc chloride, which is hygroscopic, absorbs suflicient; wa-

' ter from the atmosphere to cause the oxychloride reaction to occur and to bond the coating into a water-insoluble inorganic mass. Thereafter the coating may be washed with water or with a solution of zinc chloride. The set coating may also be washed with a coloring material. It is within the province of the present invention to include a the coloring constituent-in the original mixture,

provided the coloring constituent does not deleteriously effect the anhydrous components of the mixture.

It is desired to point out that the coating composition of the present invention fimctions in a radically different manner from prior oxychloride coatings, in that as its volatiles are driven 01!, water is taken up from the atmosphere, or any equivalent medium, to effect the hardening of the coating. In contrast thereto,.the priorcoating compositions, having a water vehicle, when applied to a surfaceby paintin spraying, or the like, harden by allowing the water toevaporate to the atmosphere. 1The coating composition of the present invention, before application, is substantially anhydrous and contains no-wa- -ter. The water necessary to allow the chemical components of the composition to react to eq ilibrium, after being applied to the surface of the object being coated, is supplied by the atmosphere, the water being absorbed from the atmosphere in the correct amount for completion of the chemical reaction functioning to harden the coating mass.

The following are specific examples of suitable coating compositions:

Example 1 4 The anhydrous zinc chloride is dissolved in the me 01 and when the solution product has coo ed, anhydrous zinc oxide is added. The mixture is about the consistency of a good painting material. The composition is brushed or sprayed onto any surface, one or two coats being applied, and the composition is kept undisturbed in the atmosphere until the components thereof have reacted and the mass threofrhas become hard and substantially water-insoluble.

Example 2 Anhydrous zinc chloride gram s Anhydrous methanol cubic centimeters-..

Dissolve and mix with:

Anhydrous zinc oxide (in fine 'powder) grams-.. 100

Silicon dioxide (in fine powder) do 20 ,The above ingredients are mixed and applied in the same manner as described in connection with Example 1. The silicon dioxide acts as a filler and also may provide a decorative eil'ect.

The above anhydrous composition contains anhydrous nickel chloride, which appears to promote the formation of the zinc oxy-chloride. Any of the above coatings may be washed with water and/or a solution of zinc chloride or with copper sulfate or any equivalent material adapted to provide the coating with a color or decora tive effect.

While the alcohols and acetones have been set forth as suitable solvents, any volatile solvent may be used, as for example any of the higher alcohols including propyl, iso-propyl, butyl and iso-butyl alcohols. Instead of using acetone which is representative of the ketones, other ketones may be used, as for example, propyl ketones, butyl ketones, or mixed ketones, as for example, methyl lso-butyl ketone. While the methanol, acetone and methyl iso-butyl ketone maybe used separately, they can also be combined to produce a composite solvent suitable for dissolving the methyl chloride.

While methanol and acetone are the preferred L solvents because of their cheapness, it is within 'terial. It may be used as a binder. in that case,

phatic character, including the cyclic, aliphatic and the cyclic aromatic compounds and their vent mixture may be selected from any of the.

prior art volatile solvent compounds, subject, however, to the provision that they have a fairly high rate of evaporation and do not delteriously react upon the ingredients of the coating composition or upon'the final oxychloride reaction product.

It is preferable that the zinc oxide should be in excess of the molecular proportions necessary for the reaction.

It is within the province of the present invention to incorporate in the anhydrous coating composition, anhydrous fillers and anhydrous organic and inorganic agents which will function to color the cementitious coating. v

More specifically, the coating mixture may be mixed with the chlorides, oxides, hydroxides, sulfates, arsenites, aluminates,-oxalates, fluorides,

phosphates, sulphides, borates, having in com-.

bination any of the following: aluminum, boron, bismuth, cadmium, calcium, barium, zinc, antimony, arsenic, lead, copper, tin, iron, cobalt, silicon, nickel, chromium, magnesium, manganese, mercury, titanium, and zirconium. While certain of these compounds will act as fillers and/r c'oloring agents, it is obvious that the present invention is not limited to the incorporation in the coating mixture of these particular compounds. In other words, the above are set forth by way of illustration. and not by way of limitation.

There may also be added to the coating composition any leveling agent which will dissolve in the solvent of the anhydrous mixture. Small proportions of carbon tetrachloride, chloroform, ether and the like function to impart to the mixture a leveling quality when the mixture is painted on to a surface. Small proportions of propyl, butyl, ethyl and methyl ketones and their compounds and derivatives when added to the solvent mixture function as leveling agents. Not only may leveling agents be added, but the mixture may have a plasticizer added thereto, as for example, tricresyl phosphate. Other organic plasticizers which may be added are dibutylthalate, castor oil, tung oil, and alkyd resin varnish.

It is obvious that instead of using the above plasticizers any plasticizer may be used which will dissolve in the anhydrous solvent of the mixture.

very satisfactory coatings, it is, obvious that it is not limited in its application as a coating mathe conversion of the binder to the oxychloride state may be promoted by humidifying an inert gas, such as air or nitrogen, or other inert gases, and passing the mixture in contact with the article in which the oxychloride cement acts as a binder, the humidified gas, which may or may not be heated, functioning to cause the volatile;

' solvent to evaporate and simultaneously supply the aqueous component necessary for the oxychloride reaction.

It is desired to point outthat the fillers may be either organic or inorganic in character. The organic fillers may be wood, cellulose compounds, or cellulose derivatives, paper, or organic waxes, all of the above components being present in the mixture in an anhydrous condition.

The composition of the present invention may be kept indefinitely'in air-tight containers, such as cans, and the cement is not formed .until water is added thereto, or until it is painted upon a surface and absorbs the moisture from the air or other medium. Therefore, the composition of the present invention may be packaged and sold as an article of commerce. The present in-' vention in its broadest phase includes the composition of matter and the production of articles carrying said composition of matter, irrespective of the function of the oxychloride cement. The

invention in its more limited aspect is directed to the production of protective metal oxychloride coatings, and articles carrying saidcoating.

Referring to Example 3 it is to be noted that there is present in the anhydrous mixture anhydrous nickel chloride which, functions as acatalytic agent. It is within the province of the concrete, or metal, which has not been previously painted, may in some cases have a smooth surface. ,In accordance with the present invention prior to applying the oxychloride coating, the smooth surface may have applied thereto an inorganic or organic priming coat preferably containing a frit, which will bond to the smooth surface. 'When the p i g coat dries there will be exposed a rough surface upon which the oxychloride coating may be applied.

The oxychloride coating of the present invention, and particularly zinc oxych10ride coating, is, unaffected by the sun or its rays, as there is nothing in the coating constituents .which will burn, as is true of ordinary paints". When the oxychloride coating is applied over ordinary paint it protects the paint from the action of the meat, and articles made of wood and composition articlesmay be treated with the putty.

The composition of the present invention may be moulded into suitable shapes and may also be used as a plastic.

It is obvious that the composition has many uses besides those specifically set forth, it being pointed out that the said uses are set forth by way of illustration'and not by way of limitation.

What is claimed is: 4

l. The method of forming a cementitious coating on a base member comprising applying to the surface thereof an anhydrous mixture of zinc chloride dissolved in a volatile anhydrous solvent for the zinc chloride and zinc oxide, theproportions of zinc chloride, zinc oxide and solvent being such that a fio'wable mixture capable of brushing or spraying is produced, said mixture on volatilization of the solvent and in the presence of an aqueous medium forming zinc oxychloride; and exposing said anhydrous coating to the action of an aqueous medium in aquantity sufllcient to form in situ a hardened zinc oxychloride coat- '2. The method of forming a cementitious coating on a base member comprising applying to the surface thereof an anhydrous mixture including zinc oxide, zinc chloride, and a. volatile solvent for the zinc chloride, the proportions of zinc oxide, zinc chloride and solvent being such that a nowable mixture capable of brushing or spraying is produced, said mixture on volatilization of its solvent and in the presence of an aqueous medium forming a zinc oxychloride; and exposing said anhydrous coating to the action of air containing an aqueous mediumin a quantity sum cient to form in situ a hardened zinc oxychloride coating.

3. The method of forming a cementitious coating on a base member comprising applying to the surface thereof an anhydrous mixture including zinc oxide, zinc chloride and a volatile solvent containing acetone as its essential component, the proportions of zinc oxide, zinc chloride and solvent being such that-a flowable mixture capable of brushing or spraying is produced, said mixture on volatilization of its solvent and in the presence of an aqueous medium forming a zinc oxychloride: and exposing said anhydrous coating to the action of air containing an aqueous medium in a quantity suflicient to form in situ a hardened zinc oxychloride coating.

' 4. The method of providinga member with an oxychloride constituent comprising mixing the anhydrous body ingredients of the member with an anhydrous mixture including zinc oxide, zinc chloride and a volatile solvent for the zinc chloride, said mixture on volatilization of the solvent and in the presence of an aqueous medium form-. ing a zinc oxychloride, forming the article there-.

from and exposing the article to the action of water to form a zinc oxychloride constituent.

,flll cracks or apertures in the surfaces of various articles. More specifically, concrete, ce-

5. The method-of forming a cementitious coating on a base member comprising applying to the surface thereof an anhydrous mixture comprising zinc oxide and zinc chloride dissolved in g a volatile solvent for the zinc chloride adapted to prevent said components from forming a hardened zinc oxychloride cement until said volatile,

- -solvnt is volatilized and the mixture is exposed to 11 aqueous medium,.the proportions of zinc oxide, zinc chloride and solvent being such that a flowable mixture capable of brushing or spraying is produced; and exposing said anhydrous coating to the action of an aqueous medium in a suillcient quantity to form in situ a hardened zinc 15 oxychloride coating.

, 6. The method of forming a cementitious coating on a base member comprising applying to the surface thereof an anhydrous mixture comprising zinc oxide and zinc chloride dissolved in a volatile solvent containing methanol as its essential component, said mixture being adapted -to prevent said components from forming a hardened zinc oiwchloride cement until said volatile solvent is volatilized and the mixture is exposed to the atmosphere, the proportions of zinc oxide, zinc chloride and solvent being such that a flowable mixture capable of brushing or spraying is produced; and exposing said anhydrous coating to the actionfof the atmosphere whereby there is formed by an in situ reaction a hardened zinc oxychloride coating.

7. As a new composition of matter, an anhydrous mixture containing zinc oxide and zinc chloride substantially completely dissolved in a volatile solvent for the zinc chloride adapted to prevent said components from forming a hardened zinc oxychloride cement until the volatile solvent is volatilized and the mixture is exposed to the action of the atmosphere.

8. As a new composition of matter, an anhydrous mixture containing zinc oxide and zinc chloride substantially completely dissolved in a volatile solvent containing methanol as its essential component, said solvent being adaptedto pre- 5 vent saidcomponents from forming a hardened zinc-oxychloride cement until the volatile solvent is volatilized and the mixture is exposed to the action of the atmosphere;

9. An anhydrous coating composition adapted 50 to be applied to a base member, said coating composition containing zmc oxide and zinc chlo- ,ride dissolved in a volatile solvent adapted to prevent said components from forming a harde'ned zinc oxychloride cement until the volatile 5 solvent is volatlized and the mixture is exposed to contactwith anaqueous medium, the latter functioning to promote the formation of a hardened zinc oxychloride coating, the proportions of zinc oxide, zinc chloride and solvent being such so that a flowable mixture capable of brushing or sprayingisproduced. i

GEORGE SIDNEY SMITH. 

